Multiple fuse



June 23, 1942. H ALTSCHULE 2,287,010

MULTIPLE FUSE Filed Feb. 24, 51941 INVENTOR ji'erman/Ataahzde/ ATTORNEY Patented June 23, 1942 MULTIPLE FUSE Herman Altschule, Newark, N. J., assignor to Utility Electric Corp., East Newark, N. J., a corporation of New Jersey "Application February 24, 1941, Serial No. 380,121

(Cl. 2oo 125) '5 Claims.

This invention relates to new and useful improvements in multiple fuses, and particularly in plug fuses of the indicator type.

It is the object of the present invention to provide a. multiple indicator fuse which can be tion of a multiple fuse assembled in accordance with the present invention;

Fig. 1-a is a horizontal cross-section along lines ia-la of Fig.1;

Figs. 2,. 3, and 4 are vertical cross-sections of three modifications oi the arrangement of the explosion chamber;

Fig. 5 is a vertical cross-section of a. modified mounting for the resistor; and

Fig. 6 a cross-section of a modified mounting for the gaseous discharge tube.

Referring now to thedrawing, l is a base substantially cup-shaped with its upstanding straight side walls 2 enclosing the combustion chamber. The base I is made of porcelain and has a central perforation 2 through its bottom. The bottom of the chamber adjacent the side wall 2 is provided with a circumferential annular groove 4. The outside of the side wall 2 is provided with a helical ridge 5 which constitutes a screw thread with which a screw-threaded shell 5 cooperates. The inside surface of the side wall 2 is provided with a plurality, e. g., six vertical grooves extending from the annular groove 4 all the. way to the lip or rim of wall 2. These grooves are equidistant and within each groove is placed a fusible link I made of zinc or the like. One end of each link 1 projects down to the bottom of the annular groove 4 and theother end is bent around the rim of the wall as indicated at 8. These links are each approximately 1; of an inch wide and contain a weakened portion about {a of an inch wide located in the vertical portion of the link. The links I are held firmly in position by a flange 9 formed in theshell 6.

In assembling the fuse, first the links I are put in place in the base and clamped by means of the shell 6. Then acopper rivet I is inserted through the central perforation 3 until head H of the rivet engages the bottom of the base I.

, The next step is to slip a contact wiper l2 over the rivet l0 until it comes to rest on the bottom of the combustion chamber. The wiper is formed out of a phosphor bronze spring, the end of which, as indicated at i3, is bent around the rivetv ill. The wiper l2 engages the links 1 and also the wall between the links and will thus be cleaned when it is rotated from one link to the next.

On top of the wiper I2 is placed a fiber disk l4 having an ear I! and a central perforation through which the rivet projects.

The next operation is to place on the base, as thus farassembled, a top or cover l6 formed of any suitable insulating material. The cover It has three concentric annular sleeves projecting from the bottom face thereof, l1, l8, and IS. The first sleeve projects near the rim of the top l6 on'the outside of shell I slightly below the rim of wall 2. The second sleeve l8 has such an outside diameter that it fits within the explosion chamber adjacent links 1. sleeve is projects within the annular groove 4 in the bottom of the chamber. A longitudinal slot 20 is formed in the sleeve H from the open lower endup to a point slightly below the rim of the wall, and having a width of about a; of an inch corresponding to the width of a link 1. The wiper '2 projects through this slot 20 into engagement with the side wall of the chamber and so does the finger l5 formed in the fiber washer ll. The third sleeve is surrounds the rivet Ill and terminates on top of the fiber washer M. This sleeve is open through a central perforation in top 18 around which a depression 22 is formed. A metal washer 23 is placed within the depression 22 and the projecting end of the rivet i0 is headed over as indicated at 24 to clamp together the whole assembly.

A resistor 25 is then placed into an opening 26v in top l6 until it comes to rest on the turnedin flange 9 of the shell 6 which is in alignment with the opening 28. The resistor 25 is held down against the flange 9 by a leaf spring 21 which is fastened to the top i'i by means of a drive screw 28.

An electric gaseous discharge or incandescent lamp is now connected in place above cover II. The lamp has a glass envelope l0 enclosing, in a neon atmosphere, two electrodes II from which lead-in wires 32 and 23 pass through the envelope to the .outside. Lead-in wire 32 is soldered to screw 28 and lead-in wire 33 to the head of rivet I I.

A cover 34 having an opening 25 is placed over lamp 3! and'i'astened to top It by any suitable means, such. as a ridge (not shown) projecting troln l5 and resiliently engaged by cover 24.

Theendof- The plug is now fully assembled and in condition to be screwed into the customary fuse socket having a shell cooperating with the screw shell 8 and a central terminal engaged by head. H of rivet l0. When the fuse is thus in position an electrical circuit is closed from the central terminal to the fuse socket through rivet l0, wiper l2, fuse link I on which the wiper is resting. shell 6, to the shell of the socket. If there is a sudden surge of excessive current or short circuit in the supply circuit, the link will fuse breaking this circuit and permitting the fiow of sufllcient current in the lamp circuit so that the lamp will light. This lamp circuit may be traced over rivet I0, lead-in wire 33, electrodes 3i, leadin wire 32, wiper 21, resistor 25 and shell 8.

When the lighting of the lamp 3| is noticed. the top It is rotated and the wiper l2 and fiber made of a separate piece I90 which has special heat resistant qualities to protect the rivet. The fiber washer l4 and all the other parts will be the same as in Fig. 1.

The resistor 25. as shown in Fig. 5, may be held within an opening 42 provided in the lower face of top lid and having a small hole 43. Within the cavity a coiled spring 21d is provided. the end of which projects through the opening 43 for connection with the lead-in wire 32.

In the embodiment shown in Fig. 6, instead of providing a separate lamp cover 34, the top He disk H are forced torotate therewith on account of their engagement by the lateral walls of the notch in the second sleeve l8 formed in the top. The rivet ill will also turn with the top as will the resistor which is held in firm engagement with the flange 9 by the spring 21. The fuse will be ready for a second operation when the wiper l'! is stopped on the next link 1.

The products of combustion from the fusing of a link I will travel from the annular chamber formed between sleeves l8 and I! through the slot 20, and then out between the contacting surfaces of top l6 and shell 6 which do not fit very I fiber disk It, a cup is formed having a side wall Illa and a bottom Ila. The diameter of the cup is the same as the diameter of the sleeve l8, and the bottom Ila corresponds to the fiber disk H and rests on top of the wiper l2. The upper ends of the side wall Illa project within a sector shaped groove 4| provided in the lower face of top I611. The side wall Illa has a longitudinal notch 20a cut therein corresponding to notch 20 in the sleeve It so as to aflord'as large an explosion chamber as is feasible. In all other respects the construction and assembly will be identical with Fig. 1.

In the modification shown in Fig. 3. top lib is again provided only with two downwardly projecting sleeves; no and I911. The fiber washer I 4 of Fig. 1 is retained and the inside sleeve i9'b has the same length as sleeve I! has in Fig. 1. In fact, the only difference between Figs. 1 and 3 is that instead of being integral with the top It, the second sleeve is formed as a separatepiece lflb having a vertical notch 20b through which the finger I5 on washer I4 and the wiper l2 project. The lower end of llb is seated in the groove 4 and the upper end within a groove lib formed in the lower face of the top IN).

The constructions shown in Figs. 2 and 3 permit the use in the walls of the sleeves Ila and Nb materials having greater resistance to heat than is required for the top I6.

Fig. 4 shows still another embodiment in which the first and thesecond sleeves I10 and [8c are integral with top lie. The third sleeve is is provided with a rim 45 within which is seated a window 46 of Plastocele or other suitable transparent material. The discharge lamp is provided within the cavity thus formed and may be viewed through the window 48.

Other modifications will be obvious to those skilled in the art without departing from the spirit of the invention defined in the claims.

What is claimed is:

1. In a multiple fuse, a base having a bottom and side walls enclosing an explosion chamber;

a plurality of fusible links within said chamber against the side wall; a metal shell around said base and connected with said links; a rotatable top for said base; two concentric sleeves within said chamber the first projecting from the bottom to the top of the chamber and the second from a point above the bottom to the top; a rivet projecting through the base and one of said sleeves; a wiper mounted on said rivet projecting through a slot in one of said sleeves into contact with the links; a resistor directly contacting with said shell and rotatable with the "top; and an electric lamp above said top connected between the rivet and said resistor.

2. In a multiple fuse, a base having a bottom,

I and side walls enclosing an explosion chamber;

a plurality of equally spaced fusible links within said chamber against the side wall; a. screwthreaded metal shell around said base and connected with said links; a rotatable top for said base; two concentric sleeves within said chamber the first projecting from the bottom to the top of the chamber and the second from a point above the bottom to the top; a rivet projecting through the base, one of said sleeves and said top; a wiper mounted on said rivet and projecting through a slot in one of said sleeves into contact with the links; a resistor projecting into direct engagement with said shell through a perforation of said top and rotatable therewith; and an electric lamp above said top having a lead-in wire connected to the rivet and a second lead-in wire to said resistor.

3. In a multiple fuse, a base having a bottom and a side wall enclosing an explosion chamber; a plurality of equally spaced fusible links against the inside surface of the side wall with their ends bent over the rim thereof; a screw-threaded metal shell around the base and clamping the bent-over ends of the fusible links; a rotatable top for said base. having two concentric sleeves projecting into the chamber, the first adjacent the wall to the bottom and having a longitudinal slot of substantially the same width as one of said links. and the second centrally to a point above the bottom; a rivet projecting through and holding together the base, said second sleeve and said top; a contactor having one end fastenedto said rivet and the other end formed into a wiper projecting through the slot in the first sleeve into contact with the side wall and the links; a washer on said rivet between said contactor and the lower end of the second sleeve and closing the chamber formed between the first and second sleeves with an ear projecting within the slot, said contactor and washer being rotatable with said top; a resister projecting through a perforation of said top and rotatable therewith; a spring pressing said resistor into direct engagement with the shell; an electric lamp above said top and having a lead-in wire connected t said rivet and a second lead-in wire connected to said resistor; and a cover for said lamp on said top., 4. In a multiple fuse plug,'a cup-shaped porcelain base the bottom of which is perforated and has a circumferential annular groove in the inside surface from which rise a plurality of equal- 1y spaced vertical grooves in the side wall up to the lip, and a helical ridge formed in the outside surface of the side wall; a fusible link within each vertical groove with one end projecting in said annular groove and the other end bent over the lip, and having a weakened portion between said lip and annular groove; a screwthreaded metal shell engaging said helical ridge and having a turned-in flange seated on the lip of the base and clamping the bent-over ends of the fusible links; a rotatable top for said base having a cover and three concentric sleeves projecting therefrom, the first near the edge to a point slightly below the lip of the base on the outside of said shell, the second within said annular groove in the base and having a longitudinal slot of substantially the same width as one of said fusible links, and the third centrally within the second and extending to a point above the bottom of the base; a copper rivet projecting through the perforation in the bottom of the base and'said third sleeve and having a head engaging the bottom of said base and a second head above the cover ofsaid top; a metal washer in a recess of said cover engaged by the second head of the rivet, said rivet and washer being rotatable with said top; a metal contactor having one end surrounding said rivet at the bottom of the cup and the other end formed into a wiper projecting through the slot in the second sleeve into contact with the inside wall of the base and the links within the grooves; an insulating washer on said rivet clamped between said contactor and the lower end of the third sleve and closing the chamber formed between the third and second sleeves with an ear projecting into the slot, said contactor and washer being rotatable with said top; a resistor projecting through a perforation of said cover between the first and second sleeves and rotatable therewith; a leaf spring having one end fastened to said cover and the free end bearing against said resistor to press it into engagement with the shell flange; a gaseous dischcarge lamp having a lead in wire connected to the second head of said rivet and a second lead-in wire connected to said spring; and a cover for said lamp fastened to said top and having an opening through which the lighting of said lamp can be observed.

5. In a multiple fuse plug, a base having a bottom and side walls enclosing an explosion chamber; a plurality of equally spaced fusible links against the inside surface of said chamber; a screw-threaded metal shell around said base and in contact with said links; a rotatable top for said base; two concentric sleeves within said chamber, one integral with the top and the other separate; a rivet projecting through the base, one of said sleeves and said top; a wiper mounted on said rivet and projecting through a slot in a sleeve and into contact with the links; a resistor mounted on and rotatable with said top, there being a direct connection between said shell and resistor in all positions of the latter; an electric lamp connected between said rivet and resistor: and a cover for said lamp on said top.

HERMAN ALTSCHULE. 

